what everyone wants is an intersection, not a union of categories. so if i click cat A and cat B, what’s returned is posts matching only A + B, not everything in A and everything in B. is this correct?
well, in case anyone is still looking for this, i was going crazy trying to figure it out but i managed a solution.
the code is here https://pastebin.com/djHB1hcA
basically the first half is the code that is returned when the user submits the form. it parses the checkboxes, and puts that into a query to display only an intersection of the two.
the second half of the code is the creation of the form and the checkboxes. I’ve separated the checkboxes by parent category for my own reasons, but all you need to do if you aren’t using subcategories is to replace the ‘for each’ query with the appropriate call.
